"These findings sit comfortably with economic theories of crime because they suggest that crime rates fall when the rewards associated with legal activity or the costs associated with illegal activity increase."

Dr Weatherburn said there were also likely to be other factors driving down the crime rate, such as "changes in vehicle and household security and changes in police tactics".

NSW Police Commissioner Andrew Scipione said NSW had made great strides in policing strategy.

"We've determined that this is now a science so we use every scientific method available to us - be it enhanced forensic services, or the way we actually task and deploy our officers," he told reporters.

But it was the sheer hard work of police officers and better community engagement that was key to driving down crime rates, he said.

"If we take our foot of the accelerator it will go right back to where it was," he said.

"In our business, there is no such thing as a finish line."

Police Minister Michael Gallacher said some categories of crime in NSW were now at the lowest recorded levels in over 20 years.

"It is clear that the O'Farrell government's ongoing commitment to combating crime, through crime prevention techniques and active policing is working," he said in a statement.

"This report highlights that the overall rate of theft in NSW is now less than half what it was in 2000.

"Over the last five years, property crime has gone down on average each year by 2.5 per cent."

Mr Gallacher paid tribute to the hard work of police in driving down crime.